Try downloading the latest Java update. Use the JRE offline installer & remove your current Java version(s), via Add/Remove Programs, before installing this one.
Java SE Downloads

If that doesn't help, delete LW's preferences folder when LW's properly closed. See point 3 here & also point 2 if you've used older versions of LW in the past (there could be a folder in either location).
Fixes for LimeWire when LW isn't operating as it should
This will change all of your settings within LW's options, you'll have to go back through afterwards & reset things. If you're not sure of your settings, go through LW's tools > options & write them all down, so that you can reset things later.
Vista users: LimeWire Pref Folder in Vista